Manufacture of sulphonated amino anthraquinone



v ring. The resulting almost colourless powder consists of the bisulphate of a-aminoanthraquinone.

The sulphate is placed in a vacuum oven,

so constructed that the powder may be spread ina thin layer, and heated to 24U-245 Cxfor 3 hours. After cooling, the powder is boiled with 4000 partsof water, the solutionltered to remove a smallamount of insoluble matter,

andthe filtrate salted with 400 parts of com- Y mon salt. l-aminoanthraquinone-Q-sulphonate ofjsodium is thus obtained in orangecoloured needles. They yield is approximately-90 per cent of the theoretical. Y

'Example 2.-(From crude 0n-aminoa'nt-hra,-

, jquiwne) Y The preparation of the sulphate is carriedY out'. as in theprevious example, but'without purifying with nitrobenzene.

-Crude a-aminoanthraqui the formation of polymolecular condensation products of a-aminoanthraquinone if the tem-y perature inthe baking ofthesulphate is carried too high. :If on the other hand the .tem-

Vperature is ftoo low a large proportion of Vthe0L-aminoanthraquinone is recovered unchanged. 1' It is found, however, that if.the

temperature is maintained between 220,-2300 Y Caafyieldof'Y per cent of the-'theoretical' llfquinone sulphonic acid, boilingthe reactionj amount of l-aminoanthraquinone-2-sulphonate of sodium may be obtained in the manner above described. f

What'we claim land desire; to secure by Letters Patent is Y Y Y1. In the Vmanufacture of l-aminoanthra-.v

quinone-Q-sulphonic acid,y the process which comprises formlng an aqueous pasteV comprising a sulphate of alpha-aminoanthr'aqumone-Z-sulphonic acid, .the step which.

quinone containing aminoanthraquinone and sulphuric acid in the molecular ratio l to 1.0'- S 1.5, drying 'said' paste to produce a powder,.-`

heating said powder to a temperature Vbetween 210-245" C. to convert the said sulphate into.1-aminoanthraquinone-Q-sulphonic acid, boiling the reaction mass with water,

'iiltering the solution thus producedto remove residual vinsoluble matter and recovering the purified aminoanthraquinone sulphonic acid.

42. The process vof claim 1 in Vwhich vthe aminoanthraquinone sulphonic acid is recov- `ered in the form of its sodium salt-bysalting the same from theflltrate Y 3. In the manufacture ofl-aminoanthraqninone-Q-sulphonic acid, ythe process `which comprises forming the bisulphate of alphaaminoanthraquinone by reacting together a purified alpha-aminoanthraquinone vwith sulphuric acid,"heating said 'bisulphate atla temperature between 210 and 245 C. to Convert saidbisulphate into alpha-aminoanthranone is found usually to containinorganloV catalysts which cause mass with water, filtering the solution thus produced to remove residual amounts of insoluble matter, salting the alpha-aminoanthraquinone sulphonic acid from said solution in the form of its sodium salt by means of pha-aminoanthraquinone to;V a .temperature between 22()v and '2300 Y C. to convert vthe Ysaid 'bis'ulphate into 1aminoanthraquinone-fZ-sulphonic acid by molecularrearrangement, boiling the' reaction mass with'water, filtering the acid. i

. solution thus produced to removehresidual Y amounts of insolublel matter and recovering Ythe purified .aminoanthraquinone Sulphon'ic #5- yIn the manufacture. Iof* ,l-aminoanthra-f aminoanthraquinone prepared-by reacting Y vtogether sulphuric acid anda :purified alpha- -aminoanthraquinone, linto l-a'minoanthra-A quinone-Q-sulphonic\.A acid jby heating said bisulphate of f alpha-aminoanthraquinone at a-temperature between 2l0qandr2ll5 C.

.6.,In the manufacture of l-aminoanthra-` quinone-Q-sulphonicacid, ythe step vwhich .oompri'ses converting sulphate ofVv alpha-u aminoanthraquinone lcontaining alpha-amivnoanthraquirione and-,sulphurio acid in the Y, molecular ratioof l to 1.04.5 intol-aminof anthraquinone-Q-sulphonic 'acid by heating the said sulphate of.alpha-aminoanthraqui-4 Y comprises converting o ya sulphate of yalphaamrinoanthraquinone containingV ami-noannone at'A a f temperature between .220 1 fand 7. In the manufacture of 1-aminoanthra-- quinone-Q-sulphonic 'acid by heating,v the -K said sulphateV of` alpha-aminoanthraquinone under reduced pressurel and at a temperature between210'and2fl5o0.

3.In the manufacture kof l-aminoanthrai quinone-Q-sulphonic acid, the Vstepwhioh comprises converting Aa sulphate of jalphaf aminoanthraquinone containingl `aminoan.-

..thraquinonej andjsulphuric acid in the 4molecular ration-lite 1.0-1.5, into l-aminoanthraquinone-Q-sulphonic acid byheatingthe saidfsulphate of alpha-aminoanthraquinone in a current of hot gas toremove water vapor as it 'isgeneratedand at, a temperature Vbe'- tween 210. and 24590. f

v9. In the manufacture. of an quinone sulphonic acid from alpha-aminoanthraquinone, -the process f which .comprises f 

